Circuit interrupter construction



Dec. 17, 1957 s. l. LlNDELL 2,316,978

CIRCUIT INTERRUPTER CONSTRUQTION Filed Feb. 24, 1954 ,5 Sheets-Sheet 1 IINVENTOR.

Dec. 17, 1957 s. I. LINDELL 2,816,978

CIRCUIT INTERRUPTER CONSTRUCTION 5 Sheets-Sheet 2 Filed Feb. 24, 1954Dec, 17, 1957 s. 1. LINDELL CIRCUIT INTERRUPTER CONSTRUCTION 5Sheets-Sheet 3 Filed Feb. 24, 1954 'izdl/ INVENTOR 5594zrdf W #M I!!! Il/ll/lllllllllllllllll Dec. 17, 1957 s. l. LINDELL cmcuxw INTERRUPTERCONSTRUCTION 5 Shets-Sheet 4 Filed Feb. 24, 1954 mw rw I I I.

wwaww INYENTOR. ficgw'd ZuzaeZL BY Dec. 17, 1957 s. 1. LINDELL CIRCUITINTERRUPTER CONSTRUCTION 5 Sheets-Sheet 5 Filed Feb. 24, 1954 2 wwfiwwzw w w l, m 5 v I wwmwwwww w United States Patent CIRCUIT INTERRUPTERCONSTRUCTION Sigurd I. Lindell, Chicago, Ill., assiguor to S & CElectric Company, Chicago, Ill., a corporation of Delaware ApplicationFebruary 24, 1954, Serial No. 412,182

44 Claims. (Cl. 200-114) This invention relates, generally, to highvoltage circuit interrupters, and it has particular relation to theconstruction of auxiliary circuit interrupters used in conjunct on withhigh voltage isolating devices, such as disconnect ng fuses,disconnecting switches and the like, for opening thern without externalarcing while they are carrying line current. This invention constitutesan improvement over the constructions disclosed in Lindell applicationSerial No. 362,891, filed June 19, 1953, now Patent No. 2,671,142, datedMarch 2, 1954, and Lindell application Serial No. 265,570, filed January9, 1952, now Patent No. 2,671,145, dated March 2, 1954, all theseapplications being assigned to the assignee of this application.

Among the objects of this invention are: To flexibly mount the auxiliarycircuit interrupter on a support that is adapted to be carried by a liveline stick for manipulation into and out of operative engagement withthe separable energized current carrying terminals or contacts of thecircuit isolating device; to provide a rigid mechanical connectionbetween the live line stick and the movable contact or terminal of thecircuit isolating device to permit positive control thereof for swingingit either to the open position or reclosing it should the operatorchange his mind and decide not to complete the opening of the circuit;to permit relative movement of the interrupter unit with respect to theaxis of the live line stick as the pin or stud of the stick follows thepath taken by the movable contact on the circuit isolating device; toposition an eye on the interrupter for engagement with a horn or stud onthe stationary line terminal or contact of the circuit isolating deviceand incline the same with respect to the longitudinal axis of the liveline stick in order to facilitate engagement with the horn or stud; toemploy spring biased universal joint means for positioning theinterrupter to facilitate engagement with the horn or stud by the eyeand then permit moving of the live line stick sidewise to cause a pincarried thereby to engage a ring, or like device, on a movable contactor terminal of the load isolating device; to hold the flexibly mountedinterrupter in fixed position with respect to the live line stick whenthe interrupter is not to be used for interrupting the circuit; toenclose the major portion of the interrupter Within an insulatinghousing; to make connection with one of the separable contacts of theinterrupter by a rigid conducting arm extending into the insulatinghousing; to provide for removing as a unit the circuit interruptingparts of the interrupter most likely to be eroded or consumed followingrepeated circuit opening operations, to control the position of the aredrawn on separation of the contacts in the auxiliary circuit interrupterin order to prevent it from impinging on contact surfaces or corners ofcontact fingers likely to be damaged; to provide for the ready escape ofthe products of the arc past one of the contacts; to mount a set ofseparable contacts for conjoint movement within the housing during whicha spring is stressed and then releasing one of the contacts to move witha snap action away from the other to draw an arc and interrupt thecircuit; to extinguish the are thus drawn; to limit the separation ofthe 2,816,978 Patented Dec. 17, 1957 ICC contacts; and to coordinate theseparation of the contacts as biased by the spring with the separationof the terminals or contacts of the circuit isolating device wherebythere is no likelihood of an arc restriking between these terminals orcontacts.

Other objects of this invention will, in part, be obvious and in partappear hereinafter.

This invention is disclosed in the embodiment thereof shown in theaccompanying drawings and it comprises the features of construction,combination of elements and arrangement of parts which will beexemplified in the construction hereinafter set forth and the scope ofthe application of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope of thisinvention, reference can be had to the following detailed description,taken together with the accompanying drawings, in which:

Figure l is a perspective view of a circuit isolating device, such as adisconnecting fuse showing how the auxiliary circuit interrupter of thepresent invention can be applied thereto, the particular circuitisolating device being that disclosed in Lindell application Serial No.367,801, filed July 14, 1953, and assigned to the assignee of thisapplication, now Patent No. 2,745,923, issued May 15, 1956;

Figure 2 is an elevational view showing how the auxiliary circuitinterrupter is mounted on a live line tool for relative movement inopposite directions with respect to its longitudinal axis in a planeparallel to the plane containing the same;

Figure 3 is an elevational view showing how the auxiliary circuitinterrupter can be held in fixed position with respect to the live linestick when it is desired to employ the latter solely for manipulating adisconnecting fuse or disconnecting switch blade;

Figure 4 is an elevational view showing the first step employed inapplying the auxiliary circuit interrupter to a circuit isolatingdevice;

Figure 5 is an elevational view showing the second step employed inapplying the auxiliary circuit interrupter to a circuit isolatingdevice, this view showing the auxiliary circuit interrupter positionedso as to provide a shunt circuit between the separable energized currentcarrying terminals or contacts of the circuit isolating device;

Figures 6 and 6A taken together provide a longitudinal sectional view,at an enlarged scale, showing the internal details of construction of anauxiliary circuit interrupter embodying this invention;

Figure 7 shows a longitudinal sectional view of the auxiliary circuitinterrupter at a reduced scale and illustrates how it is mounted on thelive line stick, the connections being the same as described for Figure5;

Figure 8 is a view, similar to Figure 7, showing the auxiliary circuitinterrupter in extended position with the latch for holding theseparable contacts in engagement in tripped position and just before anymovement of these contacts takes place;

Figure 9 is a view, similar to Figure 8, but showing the contacts in theauxiliary circuit interrupter separated with one contact being withdrawninto the bore of the liner of arc extinguishing material;

Figure 10 is a view, partly in elevation and partly in section, showingthe auxiliary circuit interrupter extended to its fullest extent, thesection being taken at right angles to the section shown in Figure 9;

Figure 11 is a sectional view taken generally along the line 1111 ofFigure 6A;

Figure 12 is a sectional view taken generally along the line 1212 ofFigure 6A and looking in the direction opposite to the direction inwhich Figure 11 is taken;

Figure 13 is a view, in side elevation, of the liner of arcextinguishing material; and

Figure 14 is a view, partly in side elevation and partly in section, ofthe inner contact sleeve.

Referring now particularly to Figure l of the drawings, it will beobserved that the reference character designates, generally, a circuitisolating device of the disconnecting fuse type. As pointed outhereinbefore, the details of construction of the circuit isolatingdevice 10 are set forth in Lindell Patent No. 2,745,923, issued May 15,1956. Accordingly, only a general description of this device will be setforth here. While particular reference is made to a disconnecting fusedevice, it will be understood that the present invention can be employedwhere the fuse tube of the disconnecting fuse is replaced by a metallicconducting tube or it can be used in conjunction with a disconnectingswitch that is modified suitably for adaptation to be used inconjunction with the auxiliary circuit interrupter mounted on a liveline stick as described hereinafter.

The circuit isolating device or disconnecting fuse 10 includes aninsulator 11 which is arranged to be stationarily mounted on a cross armor the like and has a lower terminal contact member 12 carrying aconnector 13 for connection to a line terminal. Pivoted at 14 on thelower terminal contact member 12 is a lower current carrying member 15that is positioned at the lower end of a fuse tube 16. At its upper endthe fuse tube 16 has an upper current carrying member 17 which ispositioned in contact engagement with a normally energized contactmember 18, carried by the upper end of the insulator 11. In order toremove the upper current carrying member 17 from contact engagement withthe terminal contact member 18, the former is provided with an eye orpull ring 19 of conducting material for receiving the prong of a liveline tool. In accordance with conventional practice, the fuse tube 16 ismanipulated by inserting the prong of the live line tool in the eye orpull ring 19 for swinging the upper current carrying member 17 into orout of contact engagement with the terminal contact member 18.

For purposes more fully disclosed in Lindell Patent No. 2,745,923,issued May 15, 1956, the terminal contact member 18 includes an L-shapedreinforcing bar 20 having a downwardly extending arm 21 which carries aguide 22. The guide 22 is employed, in part, for guiding the uppercurrent carrying member into proper contact engagement with the terminalcontact member 18. The guide 22 includes forwardly extending arms 23 atthe outer ends of which are transversely extending horns or studs 24.Provision is made for connecting the energized line conductor to theterminal contact member 18 through a terminal pad 25. It will beunderstood that the upper portion of the terminal pad 25 (not shown)carries a connector or like device to facilitate connection of theenergized line conductor thereto.

It is often necessary to open the circuit isolating device ordisconnecting fuse 10 while it is carrying load current. When suchoperation is performed, an arc is drawn be tween the upper currentcarrying member 17 and the terminal contact member 18 which is likely todamage the parts which are contacted by the arc and also, where othercircuits are involved, is likely to fault one or more circuits in theevent that the arc is drawn and should jump to another circuit or theground. Also there is the likelihood of injury to the operator. Inaccordance with the present invention, provision is made for safely andexpeditiously opening the circuit isolating device 10 while it iscarrying line current. It is for this purpose that the auxiliary circuitinterrupter, shown generally at 27, is employed. It will be observedthat it includes an eye member 28 which is rigid therewith and isarranged to engage one of the horns or studs 24. When the auxiliarycircuit interrupter 27 is so positioned, one terminal of it is connectedto the terminal contact member 18. Connection to the upper currentcarrying member 17 is provided by contact means in the form of a pin orprong 29 rigidly mounted and extending transversely of a supp rt memberor strut 30 that is preferably formed of aluminum and on which theauxiliary circuit interrupter 27 is flexibly mounted by a universaljoint that, generally, is shown at 31 and the details of construction ofwhich will be set forth hereinafter. The support member or strut 30 hasan extension 32, the lower portion of which forms a claw bracket 33 thatis arranged to be secured by a clamp screw 34 to a corresponding clawbracket 35 that is formed integrally with an aluminum fitting 36 at theupper end of a live line stick 37 that is formed preferably of Wood orlike insulating material. Generally the live line stick 37 is consideredto include the fitting 36 and the claw bracket 35 and may be soconsidered here.

Since the pin or prong 29 on the support member 30 loosely engages theeye or pull ring 19, it is desirable to insure that contact engagementtherewith is maintained. For this purpose a contact spring 38 is securedto the support member 30 and extends angularly outwardly therefrom forengagement with one side of the eye or pull ring 19. Since the contactspring 38 moves relatively to the pin or horn 29, it is provided with anelongated opening 39 to permit such relative movement.

As shown more clearly in Figure 2 of the drawings, the universal joint31 permits the auxiliary circuit interrupter 27 to rock with respect tothe live line stick 37 in a plane parallel to the longitudinal axis ofthe live line stick 37 for swinging the fuse tube 16 from the closed tothe open position and vice versa. Figures 3, 4 and 5 of the drawingsshow how the auxiliary circuit interrupter 27 can rock in a plane atright angles to this plane for manipulation with respect to the circuitisolating device 10 for engaging the same.

In Figure 3 of the drawings, it will be observed that the eye member 28is positioned at an obtuse angle with respect to the auxiliary circuitinterrupter 27 and is formed integrally with a contact arm 40. Thereason for positioning the eye member 28 at this angle is to facilitateits being moved into engagement with the horn or stud 24. By placing itat an angle, it is possible for the lineman to see through the openingtherein from his position at the lower end of the live line stick 37.Thus he is able to correlate the movement of the eye member 28 with theposition of the horn or stud 24.

In some instances it is desirable to manipulate the live line stick 37with the auxiliary circuit interrupter 27 r-igid therewith instead ofbeing flexibly mounted thereon. For example, when the lineman wishes toemploy the live line stick 37 solely for the purpose of performing anoperation without using the auxiliary circuit interrupter '27, it isdesirable to provide for this rigid mounting thereof. For this purpose abrace 41 is pivoted at 42 on the upper end of the support member or stud30 and it is arranged to be biased to the retracted or operativeposition .by a spring 43. At its outer end the brace 41 has a bifurcatedportion 44, the arms of which fit around the contact arm 40. Thus, whenthe brace 41 is swung from the retracted position to the position shownin Figure 3, it holds the auxiliary circuit interrupter 27 in theposition hereshown. As will appear hereinafter, provision is made forbiasing the auxiliary circuit interrupter 27 to the position shown inFigure relative to the sup port member or stud 30. Accordingly theauxiliary circuit interrupter 27 is rigidly supported with respect tothe live line tool 37 when the brace 41 is swung to its position asshown in Figure 3.

The details of construction of the auxiliary circuit in terrupter 27 areshown more clearly in Figures 6 and 6A of the drawings to whichreference now will be had. It will be observed that the auxiliarycircuit interrupter 27 is of elongated cylindrical construction. Itincludes a tubular insulating housing 47 that is formed of suitableinsulating material, such as a phenolic condensation product. Forpurposes of reference, the upper end of the housing 47 is referred to asthe inner end and at this inner end there is mounted a stationarycontact assembly .5 that is shown, generally, at 48. The stationarycontact assembly 48 includes a pull ring cap 49 that is formedpreferably of aluminum and with which the contact arm 40 (and eye member28 are integrally cast. The cap 49 is secured by adhesive means to theinner end of the housing 47 and its upper end is closed by a screw plug50. Depending from the screw plug 50 is a rigid conductor rod 51. Theinner end of the rod 51 is secured to the screw plug 50 by a snap washer52 on the underside and a nut 53 on the upper side. At its outer end therod 51 has a cam terminal 54 which is provided with a latch engagingsurface 55, the purpose of which will be :set forth presently. Dependingfrom the cam terminal 54 are a flexible conductor 56 and a coil spring57 coiled with initial tension, the latter being positioned around theformer as shown. The lowermost ends of the flexible conductor 56 andcoil spring 57 are connected to a movable first arcing contact 58 at thelowermost end of which there is an annular contact insert 59 formed of amaterial which is resistant to erosion due to impingement of an arcthereon. It will be understood that the stationary contact assembly 48includes those parts just enumerated beginning with the pull ring cap 49and concluding with the annular contact insert 59.

in order to confine the are drawn from the annular con tact insert 59 onoperation of the auxiliary circuit interrupter 27 to open a circuitunder load, there is provided a trailer 6% that is formed of a material,such as methylmethacrylate resin, which is adapted to evolve an areextinguishing medium when it is subjected to the heat of an arc. As willappear hereinafter, the trailer 60 is arranged to be drawn into the boreof .a tube which itself gives oif an arc extinguishing medium. In orderto cause the trailer 60 to move conjointly with the movable first arcingcontact 58, a trailer stud 61 is screwed into the upper end of thetrailer 6% and it extends into the movable first arcing contact 51 whereit is pivotally held by a transversely extending trailer stud pin 62.There is a limited clearance between the outer surface of the trailerstud 61 and the opening in the annular contact insert 59 and in themovable first arcing contact 58 so as to permit a limited degree ofmovement :of the trailer 60 with respect thereto. This permits it to bepositioned in the bore into which it is drawn somewhat flexibly.

A tubular metallic sleeve 65, preferably formed of aluminum, is threadedat its outer end onto the movable first arcing contact S and it extendsupwardly into the housing 47 toward its inner end. At the inner end ofthe metallic sleeve 65, there is a trigger 66 which is pivotally mountedat 67 between arms 68 of a trigger frame stop 69. A grasshopper spring71 cooperates with the trigger 66 to bias it into latching engagementwith the inner end of the tubular metallic leeve 65.

Secured by screws or other suitable means to the underside of thetrigger frame stop 69 is a metallic tu-be end insert 72 that preferablyis formed of aluminum. The insert 72 is secured by suitable means to theinner end of an inner insulating sleeve 73 that preferably is formed ofa phenolic condensation product. The inner insulating sleeve 73 isarranged to be slidably mounted within the tubular insulating housing47. It is desirable that the inner insulating sleeve 73 be guided formovement within the housing 47 so that it is non-rotatable axially withrespect thereto. For this purpose, as shown in Figure 10, longitudinallyextending slots or grooves 74 are provided in diametrically oppositepositions in the outer surface of the inner insulating sleeve 73 andtongues or pins 75 project thereinto. The tongues or pins 75 are carriedby a ring 76 that is secured to the inner surface of the housing 47 nearits outer end. The upper side of the ring 76 constitute a stop forengaging the underside 77 of the trigger frame stop 69 for limiting theextent that the inner insulating sleeve 73 can the withdrawn from thehousing 47, this position being shown in Figure of the drawtugs.

'It will be recalled that the metallic sleeve 65 is slidaible with themovable first arcing contact 58. As shown in Figure 9 of the drawings,it is movable inwardly of the housing 47 and through the innerinsulating sleeve 73. Its movement with respect thereto is limited by astop ring 78 that is secured to the outer surface of the metallic sleeve65. The stop ring 78 is arranged to engage a shoulder 79 on theunderside of the trigger frame stop 69.

As pointed out hereinbefore, the trailer 60 is drawn into a bore, thesurface of which is capable of evolving an arc extinguishing material.For this purpose a liner 80, formed preferably of methylmethacrylateresin, is positioned in the inner insulating sleeve 73 at its outer end.The liner 80 is illustrated in Figure 13 where it will be observed thereis provided a longitudinally extending groove Si arranged to cooperatewith a locating pin 82, Figure 6, for positioning the liner 80 in apredetermined location with respect to the inner insulating sleeve 73.It is desirable that there be a fairly snug fit between the outersurface of the liner 80 and the inner surface of the insulating sleeve73. Since provision is made for removing the liner 80, it is notpossible to secure this snug fit by cementing the liner 80 into thesleeve 73. Instead annular grooves 83 are provided in the outer surfaceof the liner 80 near its end and 0 rings 84 of neoprene or like materialare positioned in these grooves to seal off the space between the liner80 and the sleeve 73 to prevent are products from entering this spaceand thus preventing restriking of the arc in this space when current isbeing interrupted and a high recovery voltage is encountered.

Cooperating with the stationary contact assembly 48 is a movable contactassembly that is indicated, generally, at 87 in Figure 6A of thedrawings. It includes a metallic contact sleeve 88 that is formedpreferably of aluminum which has an extension 39 at its lower endforming a chamber 90 to receive the products of the arc. Radial vents 91serve to place the chamber 90 in communication with the atmosphere whenthe inner insulating sleeve 73 and parts associated therewith arewithdrawn from the housing 47, for example, to the position shown inFigure 8 of the drawings. Within the metallic contact sleeve 88 is aninner contact sleeve 92 which is secured in predetermined positiontherein by a contact locating screw 93. it will be understood that themetallic contact sleeve 88 is secured to the outer end of the innerinsulating sleeve 73 by suitable adhesive or other means.

As shown more clearly in Figure 14 of the drawings, the contact sleeve92 is provided with four upwardly extending flexible contact fingers 94'which have contact tips 95 of material which is are resistant. The innerends of the contact fingers 94 are arranged to have peripheral contactengagement with the movable first arcing contact 58 and moreparticularly with the annular contact insert 59, the are being drawnbetween the latter and the contact tip 95 on one of the contact fingers94. The contact fingers 94 are separated by relatively wide slots 96which extend longitudinally from the inner end to openings 97. Thepurpose of the relatively wide slots 96 is to provide for free escape ofthe products of the are drawn as described and to permit them to flowoutwardly into the chamber 90 where they can be readily vented to theatmosphere. The contact fingers 94 are biased inwardly by spring fingers98. Since the trailer 60 is required to move through the opening definedby the flexible contact fingers 94, provision is made to limit theirinward movement when not in engagement with the movable first arcingcontact 58. For this purpose a contact retaining ring 99 is employed asshown in Figure 14, the size of the ring 99 is such that, while thecontact fingers 94 are freely movable into engagement with the peripheryof the movable first arcing contact 58, as soon as it and the annularcontact insert 59 are withdrawn, the spring fingers 98 bias the contactfingers 94 inwardly but only to a limited 7 extent which is determinedby the contact retaining ring 99.

With a view to locating the arc incident to operation of the circuitinterrupter 27 so that a minimum of erosion of the contact tips takesplace, the outer end of the liner 80, as shown in Figure 11, is providedwith outllared grooves 100, each groove being individual to one of thecontact fingers 94. In Figure 12 of the drawings, the outline of thegrooves is shown by broken lines. It will be observed that the grooves190 are centered with respect to the contact tips 95. Also it will benoted that the inner edge portions 101 of the contact tips 95 aremachined otf so that the arc is drawn or initiated at the edge of thearea defined by the broken line outline of the grooves 101) from whichit is repelled and moved into the defined area by gas generated from thesurface of the trailer 60.

Referring again to Figure 6 of the drawings, it will be observed thatthe outer end of the extension 89 is closed by a hollow lighttransmitting plug 1% which. is threaded into position. The reason foremploying a material which is light transmitting for the plug 1% is topermit the lineman to note the formation of the are drawn on separationof the first arcing contact 53 from the contact tip 95 on the flexiblecontact fingers 94 which constitute a second arcing contact. By notingthe flash of the arc and its extinction, the lineman is apprised of thefact that the circuit has been completely opened and that it is safe toremove the auxiliary circuit interrupter 27 from connection to thecircuit isolating device 10.

Additional venting of the chamber 90 and the interior of the plug 103 isprovided by radial vents 104. A screen inside of the plug 103 extendsover the vents 104 and over the vents 91. The screen 105 is formedpreferably of metallic material which assists in cooling the areproducts and preventing their escape to the atmosphere. In addition, itprevents to a limited degree the ingress of foreign material.

Integral with and extending radially from the metallic contact sleeve 88is a conducting arm 1%. As shown in Figure 6A of the drawings, thconducting arm 1W6 extends radially through a slot 197 in the outer endof the housing 47. Conducting arm M6 has a portion 108, Figure 8, thatis parallel to the housing 47 and has an H-shaped cross-section. At itsupper end the portion 108 of the conducting arm 106 carries a rod 109which extends through arms 110 rigid with the support member or strutSt). The rod 1% permits the auxiliary circuit interrupter 27 to swing inthe plane of the drawing with respect to the support member or strut 30as shown in Figures 7 and 8. Springs 111, Figure 10, interacting betweenthe rod 169 and pins 112 mounted on the arms 110 act to bias theauxiliary circuit interrupter 27 in a clockwise direction with respectto the live line stick 37 or to bias the latter in a counterclockwisedirection with respect to the former.

In order to permit swinging movement of the auxiliary circuitinterrupter 27 in a plane at right angles to the plane of its movementabout the axis of the rod 1&9, a transverse shaft 113 of larger diameterthan rod 109 extends through and is journalled in the bifurcated endportion 108 of the conducting arm 106 into a pocket in the supportmember or strut 30. The rod 109 extends through and is carried by theshaft 113. A centering spring 114 surrounds the transverse shaft 113with one end 115 bearing against one side of the portion 108 of theconducting arm 106 and the other end 116 bearing against thecorresponding side of extension 32 of the sup port member or strut 3twhen the interrupter 27 is centered with respect to the live line stick37. The function of the spring 114, which is pretensioned, is to centerthe auxiliary circuit interrupter 27 with respect to the longitudinalaxis of the live line stick 37 or to bias it back to this position whenthe latter is swung relatively to the former as shown in Figure 2 by thebroken line positions of the live line stick 37 on opposite sides of theposition shown by full lines Where it is aligned with the auxiliarycircuit interrupter 27.

It is desirable to enclose the stationary contact assembly 48 at theinner or upper end of the tubular insulating housing 47. For thispurpose a removable insulating cap 119 extends over the inner or upperend of the housing 47 and encloses the contact assembly 48. The cap 119may be formed of neoprene or other flexible insulating material. It hasa longitudinally extending slot 120 on one side for accommodating thecontact arm 40.

When the auxiliary circuit interrupter 27 is in the fully closedposition with the inner insulating sleeve 73 telescoped therein, thereare no exposed energized parts on the side away from the live line stick37. Aside from the fitting 36 on the live line stick 37 and the partassociated with the support member or strut 30, the only energizedexposed parts are the eye member 28, contact arm 40 and the conductingarm 1&6. The insulating housing 47 and the insulating cap 119 serve toenclose all other conducting parts which are energized when the eyemember 28 engages the horn or stud 24 of the energized terminal contactmember 18.

It is highly desirable that provision be made for quickly and easilydismantling the auxiliary circuit interrupter 27 for the purpose ofpermitting inspection of the parts, such as the contact 58, contactfingers 94, the trailer 60 and the liner 86. The dismantling of thecircuit interrupter 2'7 can be accomplished by removing the insulatingcap 11'), loosening the nut 53 and removing the screw plug 50. Thescrews holding the trigger frame stop 69 to a metallic tube end insert72 then can be removed and the inner insulating sleeve 73 withassociated parts then can be removed through the outer end of thehousing 47. The trailer 6% then can be removed from the inner insulatingsleeve 73 together with the movable first arcing contact 58, metallicsleeve 65, the flexible conductor 56, spring 57, cam terminal 54, andconductor rod 51. Next the plug 103 is unscrewed from the extension 39and the screen is withdrawn. On removal of the contact locating screw93, the inner contact sleeve 92 can be removed to permit inspection ofthe contact fingers 94 and contact tips 95. The liner 80 is next pushedout of the inner insulating sleeve 73 for inspection. The arcing contact58 with the tubular metallic sleeve 65 and stop ring 78 can be employedfor this purpose.

In operation the lineman manipulates the live line stick 37, as shown inFigure 4, first to a position where the eye member 28 engages the hornor stud 24. Then the live line stick 37 is swung sidewise about the axisof the rod 199 to position the pin or prong 29 within the eye or pullring 19. Contact therewith is maintained by the contact spring 38.Assuming that the circuit isolating device 10 is carrying current, thecircuit between the upper current carrying member 17 on the upper end ofthe fuse tube 16 and the energized terminal contact member 18 is shuntedthrough the auxiliary circuit interrupter 27. Then the lineman exerts alongitudinal downward pull on the live line stick 3'7 with the pin orprong 29 positioned in the eye or pull ring 19 as shown in Figure 5.This initial movement causes the upper current carrying member 17 to bemoved out of engagement with the terminal contact member 18 of thecircuit isolating device 10 and the current flow formerly therethroughis transferred to the auxiliary circuit interrupter 27.

This initial movement of the live line stick 37 is accompanied by anoutward movement of the inner insulating sleeve 73 from the insulatinghousing 47. While the rigid conductor rod 51 of the stationary contactassembly 48 remains stationary, the other parts of the contact assembly48 move, as shown in Figure 8. The reason for this is that the trigger66 is in engagement with the incner end of the tubular metallic sleeve65 and the trig- 5 ger 66, being mounted on the trigger frame stop 69which is attached to the metallic tube end insert 72,-

moves with the inner insulating sleeve 73' along with the conducting arm106. The annular contact insert 59 of the movable first arcing contact58 remains in contact engagement with the inner ends of the flexiblecontact fingers 94 and the contact tips 95. The flexible conductor 56 isextended as is the coil spring 57 which is stressed.

The movement of these parts continues to the position shown in Figure 8where the trigger 66 has just engaged the latch engaging surface 55 onthe cam terminal 54 and has been moved out of latching engagement withthe inner end of the tubular metallic sleeve 65. For illustrativepurposes it is pointed out that the inner insulating sleeve 73 movesthrough about from the position shown in Figure 7 to the position shownin Figure 8 of the drawings where the trigger 66 has been moved out oflatching engagement with the inner end of the metallic sleeve 65. Thisdistance is such that the gap formed between the upper current carryingmember 17 and the terminal contact member 18 at this time issufficiently great so that there is no likelihood of an arc restrikingtherebetween. As soon as the trigger 66 is actuated, the spring 5'7retracts the movable arcing contact 58 and the trailer 69 into the boreof the liner 80. An arc is drawn between the annular contact insert 59on the contact 58 and one of the contact tips 95 on the contact fingers94. As the trailer 60 moves through the contact tips 95 and into thebore of the liner 80, one end of the arc is confined between the outersurface of the trailer 6th and the surface of one of the outfiared'grooves 190. The other end is confined between the bevelled upper end123 of the trailer 60 and the inner surface of the line 30. As thecontact 58 continues to move inwardly under the influence of the coilspring 57, the arc is confined between the outer surface of the trailer60 and the inner surface of the liner 80 where it is extinguished.

Since the first arcing contact 58 substantially fills the bore in theliner 80, the products of the arc can not flow upwardly therethrough.Rather they flow downwardly past the contact tips 95 and into thechamber 90. As shown in Figure 8 of the drawings, the chamber 90' iswell below the outer end of the housing 47 and as a result the productsof the arc and the gas pressure incident thereto can be relieved throughthe vents 91 in the extension 89' and through the vents 104 in the plug103.

As shown in Figure 9 of the drawings, the first arcing contact 58' movesinwardly of the housing 47 until the stop ring 78 engages the shoulder79 on the underside of the trigger frame stop 69. For illustrativepurposes, it is pointed out that the length of this stroke is 4%. Inthis circuit open position there is still substantial tension applied bythe coil spring 57 to the movable arcing contact 53 and the same is heldin the retracted position shown in Figure 9.

While the extent of movement of the live line stick 37 thus described issufficient to effect opening of the circuit through the interrupter 27,a further movement of'the live line stick 37 is possible and desirablein order to provide a greater separation between the contact 58 and thecontact fingers 94. In the embodiment of the invention disclosed, thisfurther movement is of the order of 3 /8" to the position shown inFigure The spring 57 is further tensioned until the ring 76 engages theunderside 77 of the trigger frame stop 69. By providing for this furthertravel and tensioning of the spring 57 abrupt stopping of the live linestick is avoided and severe shock to the interrupter 27 is obviated.

The live line stick 37 then is manipulated so as to disengage the pin orprong 29 from the eye or pull ring 19. The fuse tube 16 then swingsdownwardly under the influence of gravity to the open position. Then thelive line stick 37 is moved upwardly to lift the eye member 28 off ofthe hornor stud 24. Afterwards the auxiliary circuit interrupter 27 canbe manually restored to the closed position shown in Figures 6 and 7 bymoving the inner insulating sleeve 73 inwardly of the tubular housing 47until the trigger 66 again is in position where it engages the inner endof the metallic sleeve 65. The spring 57 goes solid and acts as a strutto transmit compressive force therethrough to cause contact 58 to engagethe contact fingers 94. In that position the annular contact insert 59'on the first arcing contact 58 is telescoped with the inner ends of thecontact fingers 94 and the contact tips 95 thereon.

In the event that some obstruction should prevent the first arcingcontact 58 and the trailer 60 from moving from their positions shown inFigure 8 to the open circuit position shown in Figure 9 under theinfluence of the spring 57, there is still a margin of movement of theinner insulating sleeve 73 which will effect the separation of thecontacts and the opening of the circuit even though the spring 57 isineffective to do so. In Figure 8 of the drawings, it will be observedthat there is still some distance between the shoulder 77 on themetallic tube end insert 72 and the ring 76. As shown in Figure 10 andas described hereinbefore, the outward movement of the inner insulatingsleeve 73 is limited by the ring 76 engaging the underside 77 of thetrigger frame stop 69. This further extent of movement is of the orderof 2 /2" in a particular embodiment and is sufficient to disengage andwithdraw the movable contact assembly 87 sufficiently far away from thefirst arcing contact 58, which is held against movement by the flexibleconductor 56 that goes taut under these circumstances, to open thecircuit and exinguish the arc. The inner insulating sleeve 73 movesdownwardly together with the liner and movable contact assembly while,as stated, the arcing contact 58 remains stationary. The are is drawnand exinguished then in the bore of the liner 80 as above described.

in the event that it is not desired to depend on the flexible conductor56 for holding the contact 58 stationary, reiiance can be placed on aring 122, Figure 6, secured to the inner end of the metallic sleeve 65.The inner periphery of this ring 122 projects over the cam terminal 54sufiiciently far that the latter will not pass through the former. Themetallic sleeve 65 then is held stationary and, since it is threaded onthe contact 58, it holds it stationary also.

The flexible conductor 56 can be omitted if sufficient contactengagement between the inner surface of the metallic sleeve 65 and thecam terminal 54 is provided as a conducting path for current flow. Thelatter can be provided with contact fingers to provide additionalengagement with the former to increase the current carrying capacity.The spring 57 can be formed of relatively good conducting material, suchas berryllium, copper, to carry the current during the interruptingoperation.

By reversing the foregoing described sequence of operations, it ispossible to close the circuit isolating device 10. In such case theinterrupter is operated first to the open circuit position and then isapplied to the device 10 also in the open circuit position. Then theinterrupter is closed and next the device 10'is operated to the closedposition. Finally the interrupter 27 is removed from the device 10 afterservice has been restored.

Since certain changes can be made in the foregoing construction anddifferent embodiments of the invention can be made without departingfrom the spirit and scope thereof, it is intended that all matters shownin the accompanying drawings and described hereinbefore shall beinterpreted as illustrative and not in a limiting sense.

What is claimed as new is:

l. Mechanism for opening a high voltage circuit isolating device such asa disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member movable into and out of engagementtherewith by manipulation of a live line stick,

said mechanism comprising, in combination, a live line stick ofinsulating material, a support member adapted to be rigidly mounted onsaid live line stick, an auxiliary circuit interrupter flexibly mountedon said support member and having limited freedom of movement relativeto said live line stick, said interrupter having contact means forconnection to said terminal contact member and additional contact meansfor connection to said movable current carrying member and when closedproviding a shunt circuit therebetween, means on said support member formechanical connection to said current carrying member wherebymanipulation of said support member by said live line stick disengagessaid movable current carrying member from said terminal contact memberwhile said shunt circuit is maintained, and means for operating saidinterrupter to open said shunt circuit after said movable currentcarrying member disengages said terminal contact member.

2. Mechanism for opening a high voltage circuit isolating device such asa disconnecting fuse, disconnecting switch or the like, normally carryngcurrent and having a normally energized terminal contact member and acurrent carrying member movable into and out of engagement therewith bymanipulation of a live line stick, said mechanism comprising, incombination, a live line stick of insulating material, a support memberadapted to be rigidly mounted on said live line stick and having contactmeans rigid with respect thereto for engagement with said movablecurrent carrying member and to operate the same into and out ofengagement with said terminal contact member by manipulation of saidlive line stick, an auxiliary circuit interrupter flexibly mounted onsaid support member and having limited freedom of movement relative tosaid live line stick, said interrupter having contact means forconnection to said terminal contact member and additional contact meansfor connection to said contact means on said support member and whenclosed providing a shunt circuit between said terminal contact memberand said current carrying member, manipulation of said support member bysaid live line stick disengaging said movable current carrying memberfrom said terminal contact member while said shunt circuit ismaintainecl, and means for operating said interrupter to open said shuntcircuit after said movable current carrying member disengages saidterminal contact member.

3. Mechanism for opening a high voltage circuit isolating device such asa disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member movable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, astrut adapted to be rigidly mounted on said live line stick and toconstitute an endwise extension thereof and having contact means rigidtherewith and extending transversely thereof for engagement with saidmovable current carrying member and to operate the same into and out ofengagement with said terminal contact member by manipulation of saidlive line stick, an auxiliary circuit interrupter flexibly mounted onsaid strut and having limited freedom of movement relative to said liveline stick, said interrupter having contact means for connection to saidterminal contact member and additional contact means for connection tosaid contact means on said strut and when closed providing a shuntcircuit between said terminal contact member and said current carryingmember, manipulation of said strut by said live line stick disengagingsaid movable current carrying member from said terminal contact memberwhile said shunt circuit is maintained, and means for operating saidinterrupter to open said shunt circuit after said movable currentcarrying member disengages said terminal contact member.

4. Mechanism for opening a high voltage circuit isolat-- ing device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member movable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, asupport member adapted to be rigidly mounted on said live line stick, anauxilary circuit interrupter flexibly mounted on said support member andhaving limited freedom of movement relative to said live line stick,resilient means interposed between said support member and saidinterrupter and biasing the latter to a predetermined position withrespect to the former, said interrupter having contact means forconnection to said terminal contact member and additional contact meansfor connection to said movable current carrying member and when closedproviding a shunt circuit therebetween, means on said support member formechanical connection to said current carrying member wherebymanipulation of said support member by said live line stick disengagessaid movable current carrying member from said terminal contact memberwhile said shunt circuit is maintained, and means for operating saidinterrupter to open said shunt circuit after said movable currentcarrying member disengages said terminal contact member.

5. Mechanism for opening a high voltage circuit isolating device such asa disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member movable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, asupport member adapted to be rigidly mounted on said live line stick, anauxiliary circuit interrupter flexibly mounted on said support memberand having limited freedom of movement relative to said live line stick,said interrupter having contact means including an eye member ofconducting material for connection to said terminal contact member andadditional contact means for connection to said movable current carryingmember and when closed providing a shunt circuit therebetween, means onsaid support member for mechanical connection to said current carryingmember whereby manipulation of said support member by said live linestick disengages said movable current carrying member from said terminalcontact member while said shunt circuit is maintained, and means foroperating said interrupter to open said shunt circuit after said movablecurrent carrying member disengages said terminal contact member.

6. Mechanism for opening a high voltage circuit isolating device such asa disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member movable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, asupport member adapted to be rigidly mounted on said live line stick, anauxiliary circuit interrupter flexibly mounted on said support memberand having limited freedom of movement relative to said live line stick,said interrupter having contact means including an eye member ofconducting material mounted thereon and inclined at an obtuse angle awaytherefrom to facilitate engagement with a horn or stud on said terminalcontact member and additional contact means for connection to saidmovable current carrying member and when closed providing a shuntcircuit therebetween, manipulation of said support member by said liveline stick disengaging said movable current carrying member from saidterminal contact member while said shunt ..circuit is maintained, andmeans for operating said interrupter to open said shunt circuit aftersaid movable 13 current carrying member disengages said terminal contactmember.

7. Mechanism for opening a high voltage circuit isolating device such asa disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingable about a fixed pivot into and outof engagement therewith by manipulation of a live line stick, saidmechanism comprising, in combination, a live line stick of insulatingmaterial, an auxiliary circuit interrupter having contact means forconnection to said terminal contact member and additional contact meansfor connection to said swingable current carrying member and when closedproviding a shunt circuit therebetween, a support member adapted to berigidly mounted on said live line tool, means flexibly mounting saidinterrupter on said support member, means on said support member formechanical connection to said current carrying member wherebymanipulation of said support member by said live line stick causes saidcurrent carrying member to swing away from said terminal contact memberwhile said shunt circuit is maintained and is accompanied by movement ofsaid interrupter relative to said normally energized contact member andto said live line tool, and means for operating said interrupter to opensaid shunt circuit after said current carrying member disengages saidterminal contact member.

8. Mechanism for opening a high voltage circuit isolating device such asa disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingable about a fixed pivot into and outof engagement therewith by manipulation of a live line stick, saidmechanism comprising, in combination, a live line stick of insulatingmaterial, an auxiliary circuit interrupter having contact means forconnection to said terminal contact member and additional contact meansfor connection to said swingable current carrying member and when closedproviding a shunt circuit therebetween, a support member adapted to berigidly mounted on said live line tool, means mounting said interrupteron said support member for pivotal movement about two axes at rightangles to each other whereby manipulation of said support member by saidlive line stick causes said current carrying member to swin away fromsaid terminal contact member while said shunt circuit is maintained andis accompanied by movement of said interrupter relative to said normallyenergized contact member and to said live line tool, resilient meansindividual to each axis and interposed between said support member andsaid interrupter for biasing the latter to a predetermined position withrespect to the former, and means for operating said interrupter to opensaid shunt circuit after said current carrying member disengages saidterminal contact member.

9. Mechanism for opening a high voltage circuit isolating device such asa disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingable about a fixed pivot into and outof engagement therewith by manipulation of a live line stick, saidmechanism comprising, in combination, a live line stick of insulatingmaterial, an auxiliary circuit interrupter having contact meansincluding a member of conducting material mounted thereon for connectionto said terminal contact member and additional contact means forconnection to said swingable current carrying member and when closedproviding a shunt circuit therebetween, a strut adapted to be rigidlymounted on said live line stick and to constitute an endwise extensionthereof and having contact means rigid therewith and extendingtransversely thereof and forming a part of the connection between saidadditional contact means and said swingable current carrying member forengaging the same to operate it into and out of engagement with saidterminal contact member by manipulation of said live line stick, meansflexibly mounting said interrupter on said strut whereby manipulation ofthe latter by said live line stick causes said current carrying memberto swing away from said terminal contact member while said shunt circuitis maintained and is accompanied by movement of said interrupterrelative to said normally energized contact member and to said live linetool, and means for operating said interrupter to open said shuntcircuit after said current carrying member disengages said terminalcontact member.

10. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingable about a fixed pivot into and outof engagement therewith by manipulation of a live line stick, saidmechanism comprising, in combination, a live line stick of insulatingmaterial, an auxiliary circuit interrupter having contact meansincluding a member of conducting material mounted thereon for connectionto said terminal contact member and additional contact means forconnection to said swingable current carrying member and when closedproviding a shunt circuit therebetween, a strut adapted to be rigidlymounted on said live line stick and to constitute an endwise extensionthereof and having contact means rigid therewith and extendingtransversely thereof and forming a part of the connection between saidadditional contact means and said swingable current carrying member forengaging the same to operate it into and out of engagement with saidterminal contact member by manipulation of said live line stick, meansmounting said interrupter on said strut for pivotal movement about twoaxes at right angles to each other whereby manipulation of said strut bysaid live line stick causes said current carrying member to swing awayfrom said terminal contact member while said shunt circuit is maintainedand is accompanied by movement of said interrupter relative to saidnormally energized contact member and to said live line tool, resilientmeans individual to each axis and interposed between said strut and saidinterrupter for biasing the latter to a predetermined position withrespect to the former, and means for operating said interrupter to opensaid shunt circuit after said current carrying member disengages saidterminal contact member.

11. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in'combination, a live line stick of insulating material, atubular insulating housing, snap acting separable contacts within saidhousing, contact means rigidly mounted on one end of said housing andconnected to one of said separable contacts and adapted to be connectedto said terminal contact member, a conducting arm connected to the otherof said separable contacts and extending outwardly of and movablelongitudinally with respect to said housing, a metallic support adaptedto be rigidly mounted on said live line stick and having contact meansfor engagement with said current carrying member to swing the same outof engagement with said terminal contact member by manipulation of saidlive line stick, means flexibly mounting said conducting arm on saidmetallic support, a shunt circuit being provided between said terminalcontact member and said current carrying member when said separablecontacts are engaged, and means responsive to movement of saidconducting arm to a predetermined position by manipulation of said liveline stick for separating said separable contacts to open said shuntcircuit after said movable current carrying member has been swung away afrom said terminal contact member a predetermined distance.

12. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, atubular insulating housing; a stationary contact assembly at one end ofsaid housing including a rigid conductor having its inner end secured tosaid one end of said housing and extending endwise into the same, acontact arm connected to said inner endof said rigid conductor andextending outwardly of said housing for engagement with said terminalcontact member, a movable first arcing cont-act in endwise spacedrelation to the outer end of said rigid conductor, conducing meansinterconnecting said movable arcing contact and said rigid conductor, aspring interconnecting said arcing contact and said rigid conductor, anda latch engaging shoulder carried by said rigid conductor; an innerinsulating sleeve slidably mounted within said tubular housing, a linerof arc extinguishing material within said inner sleeve near its outerend, a tubular metallic sleeve slidably mounted within said liner andsecured at its outer end to said first arcing contact and extending intosaid inner sleeve, and a latch carried by said inner sleeve andcooperating with said metallic sleeve to effect conjoint movement ofsaid sleeves when said inner sleeve is moved outwardly of said housing,said latch being released from said inner sleeve on engagement with saidlatch engaging shoulder to permit said first arcing contact and saidmetallic sleeve to be withdrawn through said liner under the biasingaction of said spring; a movable contact assembly including a metalliccontact sleeve secured to and movable with said inner sleeve at itsouter end, contact means carried by said contact sleeve for contactengagement with said first arcing contact and constituting a secondarcing contact, and a conducting arm extending from said contact sleeveoutwardly of said housing; a trailer of arc extinguishing materialconnected to and movable with said first arcing contact into said linerfor cooperating therewith to confine the are drawn between said arcingcontacts between the outer surface of said trailer and the inner surfaceof said liner, a metallic support adapted to be rigidly mounted on saidlive line tool and having contact means for engagement with said currentcarrying member to operate the same into and out of engagement with saidterminal contact member by manipulation of said live line stick, andmeans flexibly mounting said conducting arm on said metallic support.

l3. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, atubular insulating housing; a stationary contact assembly at one end ofsaid housing including a rigid conductor having its inner end secured tosaid one end of said housing and extending endwise into the same, acontact arm connected to said inner end of said rigid conductor andextending outwardly of said housing for engagement with said terminalcontact memher, a movable first arcing contact in endwise spacedrelation to the outer end of said rigid conductor, conducting mcansinterconnecting said movable arcing contact and said rigid conductor, asping interconnecting said arcing contact and said rigid conductor, anda latch engaging shoulder carried by said rigid conductor; an innerinsulating sleeve slidably mounted within said 16 tubular housing, aliner of arc extinguishing material within said inner sleeve near itsouter end, a tubular metallic sleeve slidably mounted within said linerand secured at its outer end to said first arcing contact and extendinginto said inner sleeve, and a latch carried by said inner sleeve andcooperating with said metallic sleeve to effect conjoint movement ofsaid sleeves when said inner sleeve is moved outwardly of said housing,said latch being released from said inner sleeve on engagement with saidlatch engaging shoulder to permit said first arcing contact and saidmetallic sleeve to be withdrawn through said liner under the biasingaction of said spring; a movable contact assembly including a metalliccontact sleeve secured to and movable with said inner sleeve at itsouter end, contact means carried by said contact sleeve for contactengagement with said first arcing contact and constituting a secondarcing contact, a conducting arm extending from said contact sleeveoutwardly of said housing, and an outer extension on said contact sleeveproviding a chamber to receive products of the are drawn between saidarcing contacts; a trailer of arc extinguishing material connected toand movable with said first arcing contact into said liner forcooperating therewith to confine the are drawn between said arcingcontacts between the outer surface of said trailer and the inner surfaceof said liner, a hollow light transmitting plug extending into the outerend of said contact sleeve extension and closing off the outer end ofsaid chamber, a metallic support adapted to be rigidly mounted on saidlive line tool and having contact means for engagement with said currentcarrying member to operate the same into and out of engagement with saidterminal contact member by manipulation of said live line stick, andmeans flexibly mounting said conducting arm on said metallic support.

14. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, atubular insulating housing; a stationary contact assembly at one end ofsaid housing including a rigid conductor having its inner end secured tosaid one end of said housing and extending endwise into the same, acontact arm connected to said inner end of said rigid conductor andextending outwardly of said housing for engagement with said terminalcontact member, a movable first arcing contact in endwise spacedrelation to the outer end of said rigid conductor, conducting meansinterconnecting said movable arcing contact and said rigid conductor, acoil spring interconnecting said arcing contact and said rigidconductor, and a latch engaging shoulder carried by said rigidconductor; an inner insulating sleeve slidably mounted within saidtubular housing, a liner of arc extinguishing material within said innersleeve near its outer end, a tubular metallic sleeve slidably mountedwithin said liner and secured at its outer end to said first arcingcontact and extending into said inner sleeve, and a latch carried bysaid inner sleeve and cooperating with said metallic sleeve to effectconjoint movement of said sleeves when said inner sleeve is movedoutwardly of said housing, said latch being released from said innersleeve on engagement with said latch engaging shoulder to permit saidfirst arcing contact and said metallic sleeve to be withdrawn throughsaid liner under the biasing action of said spring; a movable contactassembly including a metallic contact sleeve secured to and movable withsaid inner sleeve at its outer end, contact means carried by saidcontact sleeve for contact engagement with said first arcing contact andconstituting a second arcing contact, a conducting arm extending fromsaid contact sleeve outwardly of said housing, and an outer extension onsaid contact sleeve providing a Chamber to receive products of the arcdrawn between said arcing contacts; a trailer of arc extinguishingmaterial connected toand movable with said first arcing contact intosaid liner for cooperating therewith to confine the are drawn betweensaid arcing contacts between the outer surface of said trailer and theinner surface of said liner, a hollow light transmitting plug extendinginto the outer end of said contact sleeve extension and closing oil theouter end of said chamber and having one or more radially extendingvents normally closed by said housing for venting said chamber when thesame is moved out of said housing, screen means within said plugoverlying said vents, a metallic support adapted to be rigidly mountedon said live line tool and having contact means for engagement with saidcurrent carrying member to operate the same into and out of engagementwith said terminal contact member by manipulation of said live linestick, and means flexibly mounting said conducting arm on said metallicsupport.

15. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swing'able into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, atubular insulating housing having a longitudinally extending slot at oneend; a stationary contact assembly at the other end of said housingincluding a rigid conductor having its inner end secured to said otherend of said housing and extending endwise into the same, a contact armconnected to said inner end of said rigid conductor and extendingradially of said housing forengagement with said terminal contactmembet, a movable first arcing contact in endwise spaced relation to theouter end of said rigid conductor, a flexible conductor interconnectingsaid movable arcing contact and said outer end or said rigid conductor,aco'il spring surrounding said flexible conductor and interconnectingsaid arcing contact and said rigid conductor, and a latch engagingshoulder carried by said outer end of said rigid conductor; an innerinsulating sleeve slidably mounted within said tubular housing, pin andslot means in said housing and sleeve respectively to guide the latterin its movement in the former, a liner of arc extinguishing materialwithin said inner sleeve near its outer end, a tubular metallic sleeveslidably mounted within said liner and secured at its outer end to saidfirst arcing contact and extending to said'inner end of said innersleeve, a

latch carried" by said inner end of said inner sleeve and cooperatingwith the inner end of said metallic sleeve to effect conjoint movementof said sleeves when said inner sleeve is moved outwardly of saidhousing, said latch being released from said inner sleeve on engagementwith said latch engaging shoulder to permit said first arcing contactand said metallic sleeve to be withdrawn through said liner under thebiasing action of said spring; a movable contact assembly including ametallic contact sleeve secured to and movable with said inner sleeve atits outer end, a plurality of flexible contact fingers secured to anddisposed around the inner periphery of said contact sleeve forperipheral contact engagement with said first arcing contact andconstituting a second arcing contact, a conducting arm rigid with andextendingradially from said contact sleeve through said slot and alongsaid housing toward said one end thereof, and an outer extension on saidcontact sleeve providing a chamber to receive products of the are drawnbetween said arcing contacts; a trailer of arc extinguishing materialconnected to and movable with said first arcing contact into said linerfor cooperating therewith to confine the arcdrawn between said arcingcontacts 'between the outer surface of said trailer and the innersurface of said liner, a hollow light transmitting plug extending intothe outer end of said contact sleeve extension and closing oif the outerend of said chamber and having one or more radially extending ventsnormally closed by said housing for venting said chamber when the sameis moved out of said housing, a metallic screen within said plugoverlying said vents, a metallic support adapted to be rigidly mountedon said live line tool and having contact means for en gagement withsaid current carrying member to operate the same into and out ofengagement with said terminal contact member by manipulation of saidlive line stick, and means flexiblymounting said conducting arm on saidmetallic support.

16. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member swingab'le into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, atubular insulating housing having a longitudinally extending slot at itsouter end; a stationary contact assembly at the inner end of saidhousing including a rigid conductor having its inner end secured to saidinner end of said housing and extending endwise into the same, a contactarm connected to said inner end of said rigid conductor and extendingradially of said housing -for engagement with said terminal contactmember, a movable first arcing contact in endwise spaced relation to theouter end of said rigid conductor, a flexible conductor interconnectingsaid movable arcing contact and said outer end-of said rigid conductor;a coil spring surrounding said fieXible conductor and interconnectingsaid arcing conductor and said rigid conductor, and .a latch engagingshoulder carried by said outer end of said rigid conductor; aninsulating cap enclosing said inner end of said housing, an innerinsulating sleeve slidably mounted within said tubular housing, pin andslot means in said housing and sleeve respectively to guide the latterin its movement in the former, a radially inwardly extending shoulder atthe inner end of said inner sleeve, a liner of arc extinguishingmaterial within said inner sleeve near its outer end, a tubular metallicsleeve slidably mounted within said liner and secured at its outer endto said first arcing contact and extending to said inner end of saidinner sleeve, a latch carried by said inner end of said inner sleeve andcooperating with the inner end of said metallic sleeve to efiectconjoint movement of said sleeves when said inner sleeve ismovedoutwardly of said housing, said latch being released from saidinner sleeve on engagement with said latch engaging shoulder to permitsaid first arcing contact and said metallic sleeve to be withdrawnthrough said liner under the biasing action of said spring, and a stopprojecting radially from said metallic sleeve for engaging said shoulderat said inner end of said inner sleeve; a movable contact assemblyincluding a metallic contact sleeve secured to and movable with saidinner sleeve at its outer end, a plurality of flexible contact fingerssecured to and disposed around the inner periphery of said contactsleeve for peripheral contact engagement with said first arcing contactand constituting a second arcing contact, a conducting arm rigid withand extending radially from said contactsleeve through said slot andalong said housing toward itsinner end, and an outer extension'on saidcontact sleeve providing a chamber to receive products of the are drawnbetween said arcing contacts; a'trailer of arc extinguishing materialconnected to and movable with said first arcing contact into said linerfor cooperating therewith'to confine the are drawn between said arcingcontacts between the outer surface of said trailer and the inner surfaceof said liner, a hollow light transmitting plug extending into the outerend of said chamber and having one or more radially extending ventsnormally closed by 'said housing for venting said chamber when the sameis moved out of said housing, a metallic screen within said plugoverlying said vents, a metallic support adapted to be rigidly mountedon said live line tool and having contact means for en gagement withsaid current carrying member to operate the same into and out ofengagement with said terminal contact member by manipulation of saidlive line stick, and means flexibly mounting said conducting arm on saidmetallic support.

17. A circuit interrupter comprising, in combination, a tubularinsulating housing; a stationary contact assembly at one end of saidhousing including a rigid conductor having its inner end secured to saidone end of said housing and extending endwise into the same, a movablefirst arcing contact in endwise spaced relation to the outer end of saidrigid conductor, conducting means interconnecting said movable arcingcontact and said rigid conductor, a spring interconnecting said arcingcontact and said rigid conductor, and a latch engaging shoulder carriedby said rigid conductor; an inner insulating sleeve slidably mountedwithin said tubular housing, a liner of arc extinguishing materialwithin said inner sleeve near its outer end, a tubular metallic sleeveslidably mounted within said liner and secured at its outer end to saidfirst arcing contact and extending into said inner sleeve, and a latchcarried by said inner sleeve and cooperating with said metallic sleeveto effect conjoint movement of said sleeves when said inner sleeve ismoved outwardly of said housing, said latch being released from saidinner sleeve on engagement with said latch engaging shoulder to permitsaid first arcing contact and said metallic sleeve to be withdrawnthrough said liner under the biasing action of said spring; a movablecontact assembly including a metallic contact sleeve secured to andmovable with said inner sleeve at its outer end, and contact meanscarried by said contact sleeve for contact engagement with said firstarcing contact and constituting a second arcing contact; a trailer ofarc extinguishing material connected to and movable with said firstarcing contact into said liner for cooperating therewith to confine theare drawn between said arcing contacts between the outer surface of saidtrailer and the inner surface of said liner. and means for moving saidcontact sleeve outwardly of said housing to effect separation of saidarcing contacts.

18. A circuit interrupter comprising, in combination, a tubularinsulating housing; a stationary contact assembly at one end of saidhousing including a rigid conductor having its inner end secured to saidone end of said housing and extending endwise into the same, a movablefirst arcing contact in endwise spaced relation to the outer end of saidrigid conductor, conducting means interconnecting said movable arcingcontact and said rigid conductor. a spring interconnecting said arcingcontact and said rigid conductor, and a latch engaging shoulder carriedby said rigid conductor; an inner insulating sleeve slidably mountedwithin said tubular housing, a liner of arc extinguishing materialwithin said inner sleeve near its outer end, a tubular metallic sleeveslidably mounted within said liner and secured at its outer end to saidfirst arcing contact and extending into said inner sleeve, and a latchcarried by said inner end of said inner sleeve and cooperating with saidmetallic sleeve to effect conjoint movement of said sleeves when saidinner sleeve is moved outwardly of said housing, said latch beingreleased from said inner sleeve on engagement with said latch engagingshoulder to permit said first arcing contact and said metallic sleeve tobe withdrawn through said liner under the biasing action of said spring;a movable contact assembly including a metallic contact sleeve securedto and movable with said inner sleeve at its outer end, contact meanscarried by said contact sleeve for contact engagement with said firstarcing contact and constituting a second arcing contact, and an outerextension on said contact sleeve providing a chamber to receive productsof the are drawn between said arcing contacts;

a trailer of arc extinguishing material connected to and movable withsaid first arcing contact into said liner for cooperating therewith toconfine the are drawn between said arcing contacts between the outersurface of said trailer and the inner surface of said liner, a hollowlight transmitting plug extending into the outer end of said contactsleeve extension and closing off the outer end of said chamber andhaving one or more radially extending vents normally closed by saidhousing for venting said chamber when the same is moved out of saidhousing, screen means within said plug overlying said vents, and meansfor moving said contact sleeve outwardly of said housing to effectseparation of said arcing contacts.

19. A circuit interrupter comprising, in combination, an insulatinghousing having a bore from the surface of which an arc extinguishingmedium is evolved due to the heat of an arc, cylindrical contact meansin endwise spaced relation to one end of said bore and movable into andsubstantially filling the same, a trailer of insulating material capableof evolving an arc extinguishing medium when subjected to the heat of anarc and movable with said contact means into said bore, and a pluralityof contact fingers engaging the periphery of said contact means at saidone end of said bore, said housing having out flared grooves at said oneend of said bore individual to and of less peripheral extent than theportions of said contact fingers in engagement with said contact meanswhereby on separation thereof an arc drawn therebetween is confined bysaid trailer and the surface of the groove in which the arc is formed toa location intermediate the longitudinal edges of the contact fingerindividual to said groove.

20. A circuit interrupter comprising, in combination, an insulatinghousing having a bore from the surface of which an arc extinguishingmedium is evolved due to the heat of an arc, annular contact means inendwise spaced relation to one end of said bore and movable into andsubstantially filling the same, a trailer of insulating material capableof evolving an arc extinguishing medium when subjected to the heat of anarc and movable with said contact means into said bore, means extendingthrough said annular contact and interconnecting the same and saidtrailer, and a plurality of contact fingers engaging the periphery ofsaid contact means at said one end of said bore, said housing having outflared grooves at said one end of said bore individual to and of lessperipheral extent than the portions of said contact fingers inengagement with said contact means whereby on separation thereof an aredrawn therebetween is confined by said trailer and the surface of thegroove in which the arc is formed to a location intermediate thelongitudinal edges of the contact finger individual to said groove.

21. A circuit interrupter comprising, in combination. an insulatinghousing, a liner in said housing having a bore from the surface of whichan arc extinguishing me-- dium is evolved due to the heat of an arc,cylindrical contact means in endwise spaced relation to one end of saidbore and movable into and substantially filling the same, a trailer ofinsulating material capable of evolving an arc extinguishing medium whensubjected to the heat of an arc and movable with said contact means intosaid bore. and a plurality of contact fingers engaging the periphery ofsaid contact means at said one end of said bore, said liner having outflared grooves at said one end of said bore individual to and of lessperipheral extent than the portions of said contact fingers inengagement with said contact means whereby on separation thereof an aredrawn therebetween is confined by said trailer and the surface of thegroove in which the arc is formed to a location intermediate thelongitudinal edges of the contact finger individual to said groove.

22. A circuit interrupter comprising, in combination, an insulatinghousing, a liner in said housing having a bore from the surface of whichan arc extinguishing medium is evolved due to the heat of an arc, tongueand groove means on saidihousing tand liner to hold the sameinpredetermined relation, cylindrical contact means in endwise spacedrelation to one end of said bore and movable into and substantiallyfilling the same, a trailer of insulating material capable of evolvingan arc extinguishing medium when subjected to the heat of an arc andmovable with said contact means into said bore, and a plurality ofcontact fingers engaging the periphery of said contact means at said oneend of said bore, said liner having'out flared groovesat said one end ofsaid bore individual to and of less peripheral extent than the portionsof said contact fingers in engagement with said contact means whereby onseparation thereof an arc drawn therebetween is confined by said trailerand the surface of the groove in which the arc is formed to a locationintermediate the longitudinal edges of the contact finger individual tosaid groove.

23. A circuit interrupter comprising, in combination, an insulatinghousing having a bore from the surface of which an arc extinguishingmedium is evolved due to the heat of an arc, cylindrical contact meansat one end of said bore and movable into and-substantially filling thesame, a trailer of insulating material capable of evolving an arcextinguishing medium-When subjected to the heat of an arc and movablewith said contact means into said bore, and a plurality of contactfingers surrounding said trailer andengaging the periphery of'saidcontact means at said one end of said bore and extending lengthwise awaytherefrom, there being longitudinally extending slots between saidcontact fingers providing passageways for the discharge of the productsof the arodrawn on separation of saidcontact means and saidcontactfi-ngers.

24. A circuit interrupter comprising, in combination, an insulatinghousing having a bore from'the surface of which anarc extinguishingmedium is evolved due tothe heat of an arc, cylindricalcontact means atone end of said bore and movable into and substantially filling thesame, a trailer of insulating material capable of evolving an arcextinguishing medium when subjected to the heat of an arc and movablewithsaid contact means into said bore, and a plurality of contactfingers surrounding said trailer and-engaging the periphery of saidcontact means at said one end of said bore and extending lengthwise awaytherefrom, there being longitudinally extending slots between saidcontact fingers providing passageways for the discharge of the productsof the are drawn on separation of said contact means and said contactfingers, said housing having outflared grooves at said one end of saidbore individual to and of less peripheral-extent than the portions ofsaid contact fingers in'engagement with said contact means whereby onseparation thereof an are drawn therebetween is confined by said trailerand the surface of the groove in which the arc is formed to a locationintermediate the longitudinal edges of the contact fingers individual tosaid groove.

25. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand acurrent carrying member movable into and out ofengagement therewithby manipulation of a live linestick, said mechanism comprising, incombination, a live line stick of insulating material, a support memberadapted to be rigidly mounted on said live line stick, an auxiliarycircuit interrupter flexibly mounted on said support member and havinglimited freedom of movement relative to said live line stick, saidinterrupter having contact means for connection to said terminal contactmember and additional'contact means for connection to said movablecurrent carrying member and when closed providing a shunt circuittherebetween,manipulation of said support'memher by said live line stickdisengaging said movable currentcarrying member from said terminalcontact member while said shuntcircuit is maintained,'said auxiliarycircuit interrupter having a tubular'insulating housing aleng '22 sideof said support member, and means mounted on one of the last namedelements and swingable into engagement with the other for holding saidauxiliary circuit interrupter rigidly with respect to said supportmember and said live line stick.

26. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member movable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, asupport member adapted to be rigidly mounted on said live line stick, anauxiliary circuit interrupter'flexibly mounted on said support memberand having limited freedom of movement relative to said live line stick,said interrupter having contact means for connection to said terminalcontact member and additional contact means for connection to saidmovable current carrying member and when closed providing a shuntcircuit therebetween, manipulation of said support member by 'said liveline stick disengaging said movable current carrying member from saidterminal contact member while said shunt circuit is maintained, saidauxiliary circuit interrupter having a tubular insulating housingalongside of said support member, a brace pivotaily mounted on saidsupport member and swingable into operative relation to said housing forholding said auxiliary circuit interrupter rigidly withrespect to saidsupport member and said live line stick.

27. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member movable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination a live line stick of insulating material, astrut adapted to be rigidly mounted on said live'line stick and toconstitute an endwise extension thereof and having contact means rigidtherewith and extending transversely thereof for engagement with saidmovable current carrying member and to operate the same into and out ofengagement with said terminal contact member by manipulation of saidlive line stick, a contact finger connected to said strut at a positionspaced from said contact means and biased into engagement with saidmovable current carrying member to maintain contact therewith, anauxiliary circuit interrupter mounted on said strut and having contactmeans for connection to said terminal contact member and additionalcontact means for connection to said contact means on said strut andwhen closed providing a shunt circuit between said terminal contactmember and said current carrying member, manipulation of said strut bysaid live line stick disengaging said movable current carrying memberfrom said terminal contact member while said shunt circuit ismaintained, and means for operating said interrupter to open said shuntcircuit after said movable current carrying member disengages saidterminal contact member.

28. A live line handling tool for mounting on a live line stickcomprising, in combination, a strut adapted to be rigidly mounted onsaid stick, a prong carried by said strut and extending transverselythereof for engaging an energized member of an electrical device toshift it from one position to another, and a contact finger movablymounted on said strut in coplanar relation thereto and to said prong andbiased away from said strut to have engagement with said energizedmember and to maintain contact therewith, said contact finger having anelongated opening through which said prong projects.

29. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying line current comprising, in combination, an auxiliary circuitinterrupter having a relatively fixed conducting member for attachmentto a-st-a'tionary energized conducting part of said circuit isolatingdevice and a relatively movable conducting member adapted to be carriedby a live line stick means mounting said conducting members for relativemovement toward and away from each other, a contact arm on said movablemember for mechanical and electrical attachment to a movable energizedconducting part of said circuit isolating device, a pair of conjointlymovable separable contacts in said circuit interrupter connectedrespectively to said fixed and movable conducting members, movement ofsaid movable conducting member away from said fixed conducting membereffecting separation of said movable energized conducting part from saidstationary energized conducting part and conjoint movement of saidseparable contacts away from said fixed conducting member whilemaintaining a shunt circuit between said parts through said contacts,and means effective when said contacts have been conjointly movedthrough a predetermined extent to separate the same and open said shuntcircuit.

30. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying line current comprising, in combination, an auxiliary circuitinterrupter having a relatively fixed conducting member for attachmentto a stationary energized conducting part of aid circuit isolatingdevice and a relatively movable conducting member adapted to be carriedby a live line stick means mounting said conducting members for relativemovement toward and away from each other, a contact arm on said movablemember for mechanical and electrical attachment to a movable energizedconducting part of said circuit isolating device, first and secondconjointly movable separable contacts in said circuit interrupter, meansflexibly connecting said first contact to said fixed conducting member,means connecting said second contact to said movable conducting memberfor conjoint movement therewith, movement of said movable conductingmember away from said fixed conducting member effecting separation ofsaid movable energized conducting part from said stationary energizedconducting part and conjoint movement of said separable contacts awayfrom said fixed conducting member while maintaining a shunt circuitbetween said parts through said contacts, and means effective when saidcontacts have been conjointly moved through a predetermined extent tomove said first contact away from said second contact and open saidshunt circuit.

3]. A circuit interrupter comprising, in combination, relatively fixedand movable conducting members adapted to be connected to an electriccircuit, a pair of conjointly movable separable contacts in said circuitinterrupter uninterruptedly connected respectively to said fixed andmovable conducting members, means holding said contacts in contactengagement while they are being moved conjointly, movement of saidmovable conducting member away from said fixed conducting membereffecting conjoint movement of said separable contacts away from saidfixed conducting member, means for releasing said holding means, andmeans cooperating with one of said separable contacts on operation ofsaid holding means to separate the same from the other contact in thedirection of the conducting member to which it is connected to open thecircuit therethrough.

32. A circuit interrupter comprising, in combination, relatively fixedand movable conducting members adapted to be connected to an electriccircuit, first and second conjointly movable separable contacts in saidcircuit interrupter, means flexibly connecting said first contact tosaid fixed conducting member, means uninterruptedly connecting saidsecond contact to said movable conducting member for conjoint movementtherewith, means holding said contacts in contact engagement while theyare being moved conjointly, movement of said movable conducting memberaway from said fixed conducting member effecting conjoint movement ofsaid separable 24 contacts away from said fixed conducting member, meansfor releasing said holding means, and means cooperating with said firstcontact on operation of said holding means to move the same away fromsaid second contact toward said relatively fixed conducting member toopen the circuit therethrough.

33. A circuit interrupter comprising, in combination, relatively fixedand movable conducting members adapted to be connected to an electriccircuit, a pair of separable contacts in said circuit interrupteruninterruptedly connected respectively to said fixed and movableconducting members, and cojointly movable while in contact engagementmovement of said movable conducting member away from said fixedconducting member effecting conjoint movement of said separable contactstherewith away from said fixed conducting member, and spring meansincreasingly tensioned as a function of the distance said conductingmembers are relatively moved apart to move one of said contacts awayfrom the other in the direction of the conducting member to which it isconnected to open the circuit therethrough.

34. A circuit interrupter comprising, in combination, relatively fixedand movable conducting members adapted to be connected to an electriccircuit, a pair of separable contacts in said circuit interrupteruninterruptedly connected respectively to said fixed and movableconducting members, and conjointly movable while in contact engagementmovement of said movable conducting member away from said fixedconducting member effecting conjoint movement of said separable contactstherewith away from said fixed conducting member, spring meansincreasingly tensioned as a function of the distance said conductingmembers are relatively moved apart to move one of said contacts awayfrom the other in the direction of the conducting member to which it isconnected to open the circuit therethrough, latch means cooperating withsaid contacts to hold them in engagement against the biasing force ofsaid spring means, and means for releasing said latch means when saidconducting members have been relatively moved apart through apredetermined extent.

35. A circuit interrupter comprising, in combination relatively fixedand movable conducting members adapted to be connected to an electriccircuit, first and second conjointly movable separable contacts in saidcircuit interrupter, means flexibly connecting said first contact tosaid fixed conducting member, means uninterruptedly connecting saidsecond contact to said movable conducting member for conjoint movementtherewith, and with said first contact while said first and secondcontacts are in contact engagement movement of said movable conductingmember away from said fixed conducting member effecting conjointmovement of said separable contacts away from said fixed conductingmember, and spring means increasingly tensioned as a function of thedistance said conducting members are relatively moved apart to bias saidfirst contact away from said second contact toward said relatively fixedconducting member to open the circuit therethrough.

36. A circuit interrupter comprising, in combination, relatively fixedand movable conducting members adapted to be connected to an electriccircuit, first and second conjointly movable separable contacts in saidcircuit interrupter, means flexibly connecting said first contact tosaid fixed conducting member, means uninterruptedly connecting saidsecond contact to said movable conducting member for conjoint movementtherewith, movement of said movable conducting member away from saidfixed conducting member effecting conjoint movement of said separablecontacts away from said fixed conducting member, spring means tensionedas a function of the distance said conducting members are relativelymoved apart to bias said first contact away from said second contacttoward said relatively fixed conducting member to open the circuittherethrough, latch means cooperating with said '25 contacts :to *holdthem -in engageme'nt against the biasing force of saidspring-means,-and-means -for releasing said latch means whensaidcond-ucting members have been relatively :m'oved apart through .a:predetermined extent.

37. A circuit interruptercomprising, in combination, a tubularinsulating. housing. having ai conducting member secured theretocarrying. externally vextending contact makingimeans, .an innerinsulating sleeve relatively slidably mounted withinsaid housinghaving aconducting member secured thereto..carryingexternally extending contactmaking meangapair of. cojointly movable separable contacts in saidsleevecconnected respectively to said conducting members,.mov.ement ofsaid-sleeve relatively away from .said housing effecting conjointmovement of said separable 1 contacts awayfrom saidnconducting memberon. said housing, and means for separating said contacts to open thecircuit therethrough.

38. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnectingswitch or the like,normally. carryingline current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member secured thereto carrying externallyextending contact making means for electrical connection to-said contactmember, an inner insulating sleeve relatively slidably mounted withinsaid housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member, a pair of conjointly movable separablecontacts in said sleeve connected respectively to said conductingmembers, movement of said sleeve relatively away from said housingeffecting conjoint movement of said separable contacts away from saidconducting member on said housing, and means for separating saidcontacts within said sleeve as a result of its movement to a givenposition relatively away from said housing.

39. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member secured thereto carrying externallyextending contact making means for electrical connection to said contactmember, an inner insulating sleeve relatively slidably mounted withinsaid housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member, a pair of conjointly movable separablecontacts in said sleeve connected respectively to said conductingmembers, movement of said sleeve relatively away from said housingeffecting conjoint movement of said separable contacts away from saidconducting member on said housing, spring means operativelyinterconnecting said housing and one of said contacts and acting to biasthe latter for movement away from the other contact with a forcedepending upon the extent of relative movement apart of said housing andsleeve, and means for releasing said one contact for movement under theinfluence of said spring to open the circuit through said contacts.

40. Mechanism for opening a high voltage circuit isolating device suchas a disconnecting fuse, disconnecting switch or the like, normallycarrying current and having a normally energized terminal contact memberand a current carrying member movable into and out of engagementtherewith by manipulation of a live line stick, said mechanismcomprising, in combination, a live line stick of insulating material, asupport member adapted to be rigidly mounted on said live line stick, anauxiliary circuit interrupter flexibly mounted on said support memberand having limited freedom of movement relative to said live line stick,said interrupter having contact means for connection to said terminalc'ontactmember and additional contact means for connection to .saidmovable current carryingmember and*=when closed providing a shuntcircuit'therebetween, manipulation of said support member by said liveline stick'disengaging said movable current carrying member from saidterminal contact member while said shunt :circuit is maintained, saidauxiliary circuit interrupter having a tubular insulating housingalongside of said support member, and means cooperating with saidsupport member to hold the same rigid with respect to said tubularinsulating housing.

41. A circuit interrupter comprising, in combination, a tubularinsulating housing having a pair of inwardly opening spaced annulargrooves intermediate its ends, a liner removably telescoped' within saidhousing and overlying said grooves and having a bore from which an arcextinguishing medium is evolved due to the heat of an arc, resilient Oringswithin said grooves and engaging the juxtaposed outer surfaceportions of said liner to provide fluid tight sealing engagementtherewith, cylindrical contact means in endwise spaced relation to oneend of said bore and movable into and substantially filling the same, atrailer of insulating material capable of evolving an arc extinguishingmedium when subjected to the heat of an arc and movable with saidcontact means into said bore, anda plurality of contact fingers engagingthe periphery of said contact means at said one end of said bore.

42. A circuit interrupter comprising, in combination, relatively fixedand movable conducting members adapted to be connected to an electriccircuit, a pair of conjointly movable separable contacts in said circuitinterrupter connected respectively to said fixed and movable conductingmembers, movement of said movable conducting member away from said fixedconducting member effecting conjoint movement of said separable contactstherewith away from said fixed conducting member, spring means tensionedas a function of the distance said conducting members are relativelymoved apart to move one of said contacts away from the other to open thecircuit therethrough, latch means cooperating with said contacts to holdthem in engagement against the biasing force of said spring means, meansfor releasing said latch means when said conducting members have beenrelatively moved apart through a predetermined extent to permit saidspring means to separate said contacts, and means for positivelyseparating said contacts on further relative movement apart of saidconducting members in the event that the same is not effected by saidspring means.

43. A circuit interrupter comprising, in combination, an insulatinghousing having a bore from the surface of which an arc extinguishingmedium is evolved due to the heat of an arc, cylindrical contact meansin endwise spaced relation to one end of said bore and movable into andsubstantially filling the same, a trailer of insulating material capableof evolving an arc extinguishing medium when subjected to the heat of anarc and movable with said contact means into said bore, and a pluralityof contact fingers engaging the periphery of said contact means at saidone end of said bore, said housing having out flared grooves at said oneend of said bore individual to and of less peripheral extent than theportions of said contact fingers in engagement with said contact meanswhereby on separation thereof an arc drawn therebetween is confined bysaid trailer and the surface of the groove in which the arc is formed toa location intermediate the longitudinal edges of the contact fingerindividual to said groove, one root of the are being located on an endsurface of one of said contact fingers, said cylindrical contact meanshaving a surface inwardly of the peripheral surface thereof on the sidetoward and spaced from said trailer onto which the other arc root ismoved by gas generated from the 27 surface of said bore and the surfaceof the trailer by the heat of the arc.

44. A circuit interrupter comprising, in combination, an insulatinghousing having a bore from the surface of which an arc extinguishingmedium is evolved due to the heat of an arc, cylindrical contact meansin endwise spaced relation to one end of said bore and movable into andsubstantially filling the same, a trailer of insulating material capableof evolving an arc extinguishing medium when subjected to the heat of anarc and movable with said contact means into said bore, and a pluralityof contact fingers engaging the periphery of said contact means at saidone end of said bore, one root of the arc being located on one of saidcontact fingers, said cylindrical contact means having a surfaceinwardly of the peripheral surface thereof on the side toward and spacedfrom said trailer onto which the other are root is moved by gasgenerated from the surface of said bore and the surface of the trailerby the heat of the arc.

References Cited in the file of this patent UNITED STATES PATENTS1,410,888 Carlson Mar. 28, 1922 1,752,575 Roselle Apr. 1, 1930 1,910,022Legg May 23, 1933 '28 Sandin July 7, 1936 Triplett July 20, 1937 HermannJan. 14, 1941 Allison Mar. 4, 1941 Goldner Apr. 22, 1941 Ludwig et alFeb. 10, 1942 Hill Oct. 12, 1943 Schultz Mar. 14, 1944 Lindell et a1June 20, 1944 Heberlein et a1. Aug. 28, 1945 Froland Jan. 13, 1948Garrison Mar. 30, 1948 Carlson Sept. 14, 1948 Rathert Feb. 22, 1949Schultz May 29, 1951 Schultz Oct. 16, 1951 Lindell Apr. 8, 1952 LindellDec. 9, 1952 Baker Sept. 8, 1953 Milne et a1 Oct. 13, 1953 Hoye Nov. 10,1953 Kojis Jan. 5, 1954 Schneider May 31, 1955 FOREIGN PATENTS GreatBritain Nov. 2, 1933 France Feb. 27, 1952

